Air-cooled internal-combustion engine with fuel injector



April 7, 1953 I E. FLATZ 2,633,335

AIR-COOLED INTERNAL-COMBUSTION ENGINE WITH FUEL INJECTOR Filed Oct. 27, 1950 Jzzziejzz ar Emil Florz Patented Apr. 7, 1953 o i, w

AIR-COOLED INTERNAL-COMBUSTION ENGINE WITH FUEL INJECTOR Emil Flatz, Bergisch-Gladbach, Germany, signer to Kliickner-Humboldt-Deutz A. Koln am Rhine, Germany 7 Application October 2'7, 1950, Serial No. 192,590

" In Germany November 14, 1949 My invention relates to internal combustion engines with fuel injectors and directly air-cooled combustion cylinders.

' It is an object of my invention to prevent escaping fuel from reaching the cooling fins of the air-cooled cylinders while also securing a satisfactory cooling of the fuel injector valve.

During the operation of an internal combustion engine, the joints and fittings of the pressure lines or the leakage connections at the fuel injection valves of the combustion cylinders are not always completely tight be it either because of deficiencies of manufacture and assembly or due to impacts or vibrations transmitted to the fuel lines during the machine operation. When such leakage fuel reaches the cooling fins of the cylinders, it forms'together with collected dust a coating apt to severely interfere with the dissipation of waste heat by the cooling air.

It is, therefore, a more specific object of my invention to prevent any leakage fuel, that may escape from the injectionvalve or from the appertaining fittings and fuel lines, from reaching the adjacently located cooling fins of the cylinders without, however, disturbing the desired cooling effect of the air stream on the valve and the parts appertaining thereto. To this end, and in accordance with a feature of the invention, I dispose the fuel injection valve and its junction with the cylinder in the stream of cooling air at a place away from the upstream side of the cylinder, and I provide for any leakage fuel from thevalve and'its joints a gravitational and airstream path'that extends toward the downstream side of the air stream and away from the cylinder fins.

According to one of the more specific features of the invention, a guide wall is disposed between the injection valve and the cooling fins of the cylinder so that a portion of the cooling air. stream passes along the valveand carries any leakage fuel with it on the valve side of the guide wall, the cooling fins of the cylinder being screened by the wall against the possibly fuelladen portion of the stream. Depending upon the particular engine design, such a guide wall may be shaped and located to direct the fuelcontaining partialair stream into a direction different from that of the air fiow passing along the cooling fins.

When during standstill of the engine the fuel supply line is detached from the injection valve, some fuel may escape from the line or from the valve. Since then the leakage fuel is not blown away by cooling air, the above-mentioned guide 3 Claims. (01. 123-41.69)

wall according to the invention is preferably designed as a run-off path or trough for the fuel and extends to a point outside the range of the cylinder fins unless the position of the injection valve is such that the fuel will run or drip down away from the fins. In many cases it sufiices for this purpose to extend the guide wall beyond the periphery of the cylinder fins.

According to another feature of the invention, I mount the injection valve laterally or at the downstream or lee side of the cylinders relative to the flow direction of the cooling air. Depending upon the position of the combustion cylinders and. the direction of the air stream, a special guide wall can be dispensed with if the cooling air, with the lateral or lee side arrangement of the injection valve, has already the effect of blowing the leakage fuel in a direction away from the cylinder and its fins. When placing the injection valve at the lee side of the cylinder, it is preferable to locate it near or withinthe air outlet slot of the cowling which surrounds the cylinder and guides the cooling air along the cylinder fins. Although placing the valve at the lee side may appear to be unfavorable, the justmentioned slot arrangement of the valve secures a satisfactory cooling especially in conjunction with a suitable shape of the adjacent portion of the cowling. The arrangement has the further advantage that the injection valve and the fuel supply line can be introduced through the outlet slot of the cowling, thus permitting the cowling to be mounted and fastened independently of the injection valve and the fuel supply line.

According to a further feature of the invention 4 and preferably in conjunction with an arrangement of the injection valve at the lee side ofthe cylinders, a channel-shaped enlargement of the air-guiding means or a separate duct are provided which directs a partial air stream toward the injection valve separate from the air stream portion that passes along the cylinder fins. This permits improving the cooling of the valves in cases where its location would otherwise not be Well suited for the desired carrying off of leakage fuel.

The foregoing and other objects and features of the invention will be apparent from the embodiments exemplified on the drawing and described in the following. In the drawing, Fig ure 1 shows a part-sectional side view of the cylinder portion of an internal combustion engine; Fig 2 is a partial and part-sectional view of the same engine portion extending at a right angle to the view of Fig. 1; and Fig. 3 is a schematic and part-sectional side view of the cylinder portion of another engine.

The engine cylinder I according to Figs. 1 and 2 is equipped with horizontal exterior cooling fins i. A cowling 2 encloses the cylinder with its fins and provides a guide path for a stream of cooling air which is blown in through the lefthand opening of the cowling. An injection valve 4 is screwed into the head portion 3 of the cylinder and is located in the lee of the cylinder relative to the stream of cooling air. A pressure line whose coupling end is screwed to the valve 4 connects the valve with the fuel. injection pump (not shown) of the engine. The outlet opening 6 of cowling 2 has essentially the shape of a vertical slot. The valve 4 and the fittings that connect it with the line 5 are located near and partially within the slot end 6 of the cowling. Consequently, the valve as well as the fuel supply line 5 can be detached from the cylinder without requiring a preceding disassembl'y of the cowling 2.

Any leakage fuel escaping from the valve 4 or its joints with the cylinder and with the line 5 are caught by the stream of cooling air and hence are carried from the lee side of. the cylinder immediately through the outlet slot 6 into the ambient space. Consequently, in this design the leakage fuel cannot possibly drop onto the fins 1". Even when the linev 5 is disconnected from the valve during standstill of the engine, the leakage fuel will not run. onto the fins I but will. drip from the screw connection adjacent to the leakage point along a path outside the range of the fins. However, in some cases. a suitably shaped drip nose or a short. guide vane. for directing any running oif fuel away from the. cylinder fins may be added. In cases where the. axis of the engine cylinder has a. slanted or horizontal direction so that the injection valve is located at the bottom side of the cylinder, the arrangement of the injection valve in the. wind shadow of the cylinder ac.- cording to Figs; 1 and 2 is even more favorable than with an upright cylinder arrangement.

The embodiment of Figs. 1 and 2 has its cowling 2. provided with. a channel-shaped enlargement 7. which forms a duct to guide part of the incoming air stream directly toward the rearwardly located valve 4, thus improving the cool.- ing' of the valve.

In the embodiment according to. Fig. 3, the injection. valve. 4' is screwed into the cylinder head 3 from the. topside and is coaxial with the cylinder. A guide wall 8 is mounted between cylinder head and the injection valve. Wall 8 consists. of. sheet metal. and extends fromv the location of the valve and its fittings toward the. down.- stream side of the air fiow and beyond. the periphery of the cooling fins t. Consequently, any occurring leakage fuel is guided away from the cylinder to the rear side of'the cylinder. The guide wall 8 has a narrow rim turned upwardly so that any fuel which may escape when during standstill of the engine thepressure line 5 is removed is caught in the trough thus formed by the wall. The guide wall 8 extends beyond the periphery of the fins a s'uffi'cient extent to make sure thatv any fuel dripping. off the end of the wall cannot reach the fins even when the engine is at rest.

It will be apparent to those skilled in the art that my invention permits of various embodiments and modifications other than those specifically described, without departing from the objects and essence of the invention and within the scope of the claims annexed hereto.

Iv claim:

1. A directly air-cooled internal combustion engine, comprising a combustion cylinder having exterior peripheral cooling fins, a cowling substantially enclosing said cylinder, said cowling having an inlet side and an outlet slot at diametrically opposite cylinder sides and forming together with said cylinder and between said inlet side and said slot two air stream paths around both. lateral sides respectively of said cylinder, said slot extending substantially parallel to the cylinder axis, and a fuel injection valve joined with said cylinder within said cowling, said valve being disposed in said slot at the downstream merging point of said two air streams.

2. A directly air-cooled internal combustion engine, comprising a combustion cylinder having exterior peripheral cooling fins, an air-guiding enclosure structure substantially enclosing said cylinder and having an inlet opening and an outlet opening located. at opposite sides and in an axial plane of said cylinder, said structure forming together with said. cylinder and between said two openings two interstitial air-stream paths around the lateral sides respectively of said cylinder, and a fuel injection valve joined with said cylinder within said structure at a point located in said plane ahead of said outlet opening, said valve being disposed away from the air-upstream side of said cylinder and having a gravitational and air-stream path for leakage fuel extending from said valve and away from said fins to said outlet opening.

3. An internal combustion engine according. to claim 2, comprising a fuel supply line and separable connector means joining said line. with. said valve, said valve and said connector means being disposed substantially above said fins, and guide wall means disposed between said valve and said fins and extending to said outlet opening. so that fuel escaping when said line is disconnected is carried away from said fins to said outlet opening.

EMIL FLATZ.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,254,861 Smeeth Jan. 29, 1918 1,502,264 Moore July 22, 1924 1,879,140 Edwards Sept. 27, 1932 1,933,949 Weber Nov. 7-, 1933 2,025,506 Gosslau' Dec; 24', 1935 2,104,257 Heintz Jan. 4, 1938 2,140,397 Alfaro Dec. 13, 1938 V FOREIGN PATENTS Number Country Date 881,187 France Jan. 15, 1943 

